The present invention relates to a furnace for smelting non-ferrous metals and/or for holding non-ferrous metal melts. The furnace has a trough and a lid. The lid covers at least a portion of the trough and is provided on its inside with devices for transmitting heat directly to the metal melt introduced into the trough.
In known furnaces of this kind, the lid having the devices for heat transmission (heating devices) extends over only a portion of the trough. A bulkhead extending vertically from above into the trough is attached to the lid along one edge thereof, so that the portion of the trough outside the lid is divided from the portion of the trough inside the lid, begining at the lid itself, as far as a certain depth into the introduced metal melt. In this apparatus, it is not possible to put the lid on when the melt has cooled partially, because in that case the bulkhead is no longer capable of dipping into the metal melt. Such a situation may arise if there has been damage to the heating device or to some other part of the lid, the repair of which lasts at least long enough that the surface of the metal melt is already begining to cool. For this reason, in the known holding furnace, a substitute lid must always be ready at hand. Furthermore, this bulkhead is not optional because backward flows of the metal melt out of the smelting and holding chambers back toward the filling location are possible at least when the lid is open. That means that an optimally calmed (degassed) and thus purified material does not reach the drain location. This has a negative effect on the quality of the injection molded die-cast part made from the material.